IBM Keyboard

Before the world moved to using PCs as the main interface to talk to the 400, we had IBM Keyboards with keys that are now largely disappeared from the keyboards of today.

HELP KEY

Now people need to remember to use the universal F1 help key.

HEX KEY

Hex here does not mean Witchcraft but Hexadecimal which is IBM name for Base 16 that Midrange computers used to run on (it might be a higher one now). This means that while humans count from 1 to 10, the 400 counts from 1 to 15 where the single character representing 10-15 is A-F.

Before the world moved to using PCs as the main interface to talk to the 400, we had IBM Keyboards with keys that are now largely disappeared from the keyboards of today.

There were some intermediate keyboards where we had to use ALT then some key to get the HEX.